Electrostatic immobilization of cetylpyridinium chloride to poly(vinyl alcohol) hydrogels for the simple fabrication of wound dressings with the suppressed release of antibacterial agents

Polymeric systems for antibacterial wound dressings require chemical reactions or syntheses for attaching or incorporating antibacterial moieties into polymer backbones. However, these materials often fail to satisfy the basic requirements, such as easy and inexpensive synthesis. We speculated that a positively charged organic antibacterial agent would be attracted to the polar groups of poly(vinyl alcohol) (PVA) hydrogels and would show suppressed release. PVA hydrogels containing cetylpyridinium chloride (CPC) were prepared by γ irradiation. CPC was barely released from the hydrogels, probably because of electrostatic interactions, and was stable upon γ irradiation. The suppressed release of CPC conferred antibacterial activity against Escherichia coli to the surface of the hydrogels, whereas no inhibition zone was observed around the hydrogels. The CPC-containing PVA hydrogels were easy to prepare and contained known and safe materials. The simplicity and safety of this procedure for achieving the suppressed release of antibacterial agents were advantages of these CPC-containing PVA hydrogels.